The nucleic acids sequence and amino acids sequence of xynbi were homologously analysed with the sequences coding for xylanases published in genebank . the result indicated that xynb ] was the highest similarity to the gene xyli from sm ptomyces sp . strain s38 , up to 86 % 将所测出的基因xynb1的成熟蛋白部分核苷酸序列与genebank上的木聚糖酶基因序列进行同源比较，最高同源性为86 ，氨基酸序列最高同源性也为86 ，并且与之同源性最高的基因所表达的酶酶学性质与xynb酶学性质有较大差异。
Xylanase refers to a type of enzyme which can hydrolyze xylans into xylooligosaccharides and d - xylose . it broadly exists in microorganism and has wide commerical application in industrial processes , such as feed , paper , foodstuff , medicine and energy industries . the xylanase gene xynb encoding the native protein of xylanase from streptomyces olivaceoviridis a1 was cloned into pichia pastoris expression vector ppic9 a 我们将来源于橄榄绿链霉菌a1 ( streptomycesolivaceoviridisa1 )的木聚糖酶基因xynb的成熟蛋白编码序列克隆到毕赤酵母表达载体ppic9中，转化pichiapastorisgs115得到重组子，实现了木聚糖酶基因xynb的高效表达，表达产物能有效分泌且具有正常的生物学活性。
